ISSN 1008-5548

CN 37-1316/TU

2017年23卷  第6期
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垂直壁面附近细颗粒物热泳效应实验研究

Experimental study on effect of thermophoresis of fine particles near surface of vertical wall

Doi:10.13732/j.issn.1008-5548.2017.06.001
作者:夏晓康,李灿,朱尚斌

摘要:为了观测室内细颗粒物的热泳规律, 在一间环境实验舱内构造冷热垂壁区间, 用卫生香燃烧烟尘作为细颗粒物源, 采用扫描电迁移率粒径谱仪观测在不同冷热壁面温差情况下, 细颗粒数量浓度的衰减系数, 以间接对比其热泳效应。实验表明:冷热壁面在50、70、90℃温度差下, 冷壁面附近卫生香烟尘细颗粒物衰减系数依次减小, 即随着冷热壁面温度差增大, 卫生香烟尘细颗粒物趋冷壁的热泳效应增强;能够产生热泳效应的细颗粒物粒径增大, 冷热壁面温差为70、90℃时, 分别能够引起90~170、210~450 nm粒径范围细颗粒物产生明显热泳效应。

关键词:细颗粒物;热泳效应;垂直壁面

Abstract:To observe the law of indoor fine particles' thermophoresis, the incense smoke was used as the fine particles source in an environmental laboratory with an artificial hot and cold vertical wall zone, and the scanning electrical mobility sizer was used to measure the decay coefficient of fine particles number concentration near the cold wall under different temperature difference for the indirect comparision of its thermopheresis.Experimental results show that the decay coefficient of fine particles near the surface of cold wall decreases in turn under the temperature difference between the hot and cold surface of vertical wall at 50, 70, 90 ℃. That is, the greater the temperature difference near the vertical wall, the stronger the thermophoresis effect of incense smoke particles tends to be closed to the cold surface, and the larger size of fine particles with thermophoresis effect. When the temperature difference between the hot and cold surface of vertical wall are 70, 90 ℃, it results in obvious thermophoresis effect of fine particles in the range from90 to 170 nm and from 210 to 450 nm respectively.

Keywords:fine particles;effect of thermophoresis;vertical wall